Preheat oven to 325 degrees. Remove any pin feathers from turkey, and wash & dry inside &out. Cut lemon in half and rub inside of bird with one of the halves, squeezing out juice as you rub. Place both lemon halves inside turkey. cut a celery stalk into 1" pieces and quarter an onion. combine with salt, garlic, parsley, and 2 tsp herbes de provence. Place mixture inside bird. Sprinkle half the remaining herbes in the neck opening. Truss by tying the wings close to the body and legs together. Rub the outside of the turkey with the olive oil and remaining herbes. Lay turkey, breast side down, on a rack and set in roasting pan. Slice remaining celery and onion and add to pan. Add boiling water. Bake 30 minutes. Turn turkey on its side, baste with pan juices, and bake 45 minutes. Turn on its other side, baste and bake 30 minutes more. Turn turkey breast side up, baste and bake for another 45-60 minutes, basting once or twice more. to test for doneness, insert an instant-read thermometer in the thickest part of the thigh, without touching bone. The thermometer should register 180 degrees. Transfer turkey to a hot platter, cover loosely with foil, and let rest at least 15 minutes before carving.